Wilhelm von pittlee



106. COMPOSITlONS,

COATING 0R PLASTIC. firess Referen i 85 26/25? 7 uU'lIlUllBl-l h W. VON PITTLER.

ARTIFICIAL LITHUGRAPHIG STONE.

No. 326,254. Patented Sept. 15, 1885.

UNITED STATES I, I I I V j 73mm I ll PATENT OFFICE.

WILHELM VON PITTLER, OF LEIPSIG, ASSIGNOR TO WEZEL & NAUMANN,

" on RENDUJTZ, LEiPsIo, GERM any.

ARTIFICIAL LITHOGRAPHIC STONE.

SPECIFICATION forming part of Letters Patent No. 326,25 1, dated September 15, 1885.

Application filed January 8, 1885. (N0 model.)

graphic stone dlSS61V6d by muriat-ic acid and reunlted with its car on1c ac] aso, 1n the pro ess for carrying my inventlon into efl'ect. The accompanying drawings represent the apparatus for producing the artificial lithographic stone. Figure I is a vertical longitudinal section of said apparatus. Fig. II is a top view of the same.

The letter A represents a tank which is filled through opening a with crushed or powdered lithographic stone. The opening a is then hermetically closed, and muriatic acid is conducted into tank A from vessel B. The acid will dissolve the stone, and the carbonic acid will be freed and flow into vessel 0 through pipe 0. This vessel is filled with water, and. the acid in passing through the sam s relie. .1 from impurities. Finally, the ear-conic acid ente s a mixing-tank, D, through pipe d. The dlSSOhCd stone in tank is removed through a bottom opening, 6, and the muriatic acid is washed out. It is then thrown into mixing-tank D, to be remixed under pressure with the carbonic acid. The mixing is offected by mechanical ineans,which consists of a shaft, 9, having radial stirring-blades h, and receiving motion from pulley Distilled water is also admitted intotank D, so that the resultant products will be a fluid mass. This mass is placed in hermetically-sealed jars until it is used. All the vessels of the above apparatus should preferably be lined 5 with lead.

In place of usin round litho raphic stone, other stones-sum orcelain which are nmmdids EWb eTfiiployed.

Before the mixture is applied to metal plates a small quantity of silicate of )otasium hos horus sul )hur m t i in should he adds e same resu can e o tained with salt of sodium otassium, lithium barium and strontium.

' p a s prepare wit tie a ove so ution are adapted for etching, and are not affected by acids and colors.

I do not claim-to haveinvented the mixture of ground stone with carbonic acid, as such a mixture is described in Patents Nos. 139,274 'and 147,522. of D. M. Sprogle, and in Patents Nos. 149,682 and 153,020, of J. L. Rowland; but

I do clain1 v 1. As a new article of manufacture, a metal plate having a covering of crushed lithographic stone dissolved by niuriat-ic acid and reunited with its carbonic acid, substantially 0 as specified. l

2. The process of producini irtifieial lithographic stone, which consists in crushing lithographic stone, liberating the carbonic 7 acid, reuniting the stone with the acid by a 7 mechanical mixer, and finally covering metal plates with the mixture, substantially as specified.

In testimony whereof I have signed my name to this specification in the presence of So two subscribing witnesses.

WILHELM VON PITTLER.

Witnesses:

J ULIUS \VEZEL, HEINRICH LUsKE. 

